Introduction
Epidural injections are a minimally invasive, non-surgical treatment option for addressing lower back (lumbar) pain and radiating pain into the legs. This procedure involves injecting pain-relieving medications directly into or near the source of the pain in the spine, typically in an outpatient setting. Epidural injections can be highly effective for certain individuals and may be repeated over time. Once the pain is alleviated, patients may be able to participate in physical rehabilitation to improve function and mobility.
Anatomy
The lumbar spine, located in the lower back, forms the natural curve below the waist. It consists of five large vertebrae, each separated by discs that allow movement and act as shock absorbers. The vertebrae form a spinal canal that houses and protects the spinal cord.
The spinal cord is a vital part of the nervous system, running from the brain through the spinal canal. Surrounding the spinal cord is the epidural space, a cavity that contains tissue, blood vessels, and nerves.
The spinal nerves extend from the lumbar spine to the lower back, buttocks, legs, and feet, relaying sensory and motor signals between the brain and these areas. Near the first lumbar vertebra, the spinal cord tapers into a bundle of nerves called the cauda equina, which regulates bowel and bladder function.
Causes
Epidural injections are used to alleviate pain caused by conditions such as herniated discs, cysts, arthritis, fractures, spinal stenosis, or other degenerative changes that irritate nerves in the lumbar spine. Spinal stenosis, a narrowing of the spinal canal, can lead to nerve compression and pain. Nerve irritation can result in conditions like sciatica, where pain radiates from the lower back to the buttocks, legs, and feet. Epidurals can also be used to manage pain caused by cancer or shingles (post-herpetic neuralgia).
Symptoms
Symptoms associated with lumbar pain vary based on the underlying cause. Common symptoms include radicular pain that radiates to the buttocks, legs, and feet, as well as stiffness, muscle weakness, numbness, or tingling. If you experience a sudden loss of bowel or bladder control, seek immediate medical attention, as it may indicate a serious condition.
Diagnosis
To diagnose the cause of your lower back pain, your doctor will conduct a physical examination and may order imaging tests, lab tests, or nerve studies. These diagnostic tools help your physician determine whether epidural injections are a suitable treatment option for you.
Treatment
Epidural injections involve administering a combination of local anesthetics and steroids into the epidural space to reduce inflammation and relieve pain. Steroids help to decrease swelling and irritation, while anesthetics provide immediate pain relief. In some cases, a saline solution is used to flush out inflammatory chemicals. Epidural injections are commonly used to treat conditions like lumbar radiculopathy, spinal stenosis, arthritis, neuropathy, and cancer-related pain.
The procedure is a short outpatient treatment that can be performed at a surgery center, hospital, or clinic. During the injection, you will be positioned sitting up, or lying on your side or stomach. The injection area will be cleaned and numbed with a local anesthetic, and you may receive a sedative to help you relax.
Using live X-ray guidance (fluoroscopy), your doctor will carefully insert a needle into the epidural space. A contrast dye may be used to ensure proper needle placement, and hypoallergenic dye will be used for those with iodine or shellfish allergies. Once the medication is injected, the needle is removed, and you will be monitored for a short period before being discharged.
Most patients can return to their normal activities the next day, although your doctor will provide instructions on managing temporary soreness at the injection site.
